[0001] The present invention relates to a hydraulic shock absorber.
[0002] Japanese Patent Application Laid-Open (JP-A) No.
2008-8341 (Patent Document 1) discloses a hydraulic shock absorber in which a lower end of
an axle-side tube, which is slidably inserted into a vehicle body-side tube, is threadedly
engaged with an axle bracket, and a lower end of a suspension spring, which is interposed
between a vehicle body-side tube and an axle-side tube, is seated on a spring receiver
supported by the axle bracket in the axle-side tube.
[0003] Further, the hydraulic shock absorber disclosed in Patent Document 1 includes a spring
load adjusting portion, which adjusts a spring load of the suspension spring by vertically
moving the spring receiver, on the axle bracket. The spring receiver is inserted so
as to come in contact with the inner periphery of the axle-side tube and concentrically
set to the axle-side tube, and is supported to not rotate with respect to the axle
bracket by being engaged with the spring load adjusting portion.
[0004] When the hydraulic shock absorber disclosed in Patent Document 1 is assembled, the
spring load adjusting portion and the spring receiver are assembled to the axle bracket
and the lower end of the axle-side tube is threadedly engaged with the axle bracket.
In this case, as described above, the spring receiver is supported by the axle bracket
so as to not rotate with respect to the axle bracket by being engaged with the spring
load adjusting portion, and is inserted so as to come in contact with the inner periphery
of the axle-side tube. For this reason, if the axle bracket is threadedly rotated
in order to be threadedly engaged with the axle-side tube, the spring load adjusting
portion, which is rotated with the axle bracket as a single body, applies a rotation
force to the spring receiver through a point engaged with the spring receiver. Therefore,
the spring receiver is rotated about a rotation center that is a point engaged with
the spring load adjusting portion. Since the rotation center is separate from the
center axis of the axle-side tube, an outer edge distant from the rotation center
of the spring receiver is engaged with the inner periphery of the axle-side tube,
so that the rotation is locked. Accordingly, the axle bracket cannot be threadedly
rotated. Therefore, there is a concern that the axle bracket cannot be threadedly
engaged with the axle-side tube or damage of the spring receiver or the spring load
adjusting portion is caused.
[0005] An object of the present invention is to facilitate assembly of a hydraulic shock
absorber.
[0006] Another object of the present invention is to smoothly threadedly engage an axle
bracket with an axle-side tube in a hydraulic shock absorber in which a spring receiver,
which is supported by the axle bracket so as to not be rotatable with respect to the
axle bracket, is inserted so as to come in contact with the inner periphery of the
axle-side tube.
[0007] The present invention relate to a hydraulic shock absorber in which a lower end of
an axle-side tube slidably inserted into a vehicle body-side tube is threadedly engaged
with an axle bracket, and a lower end of a suspension spring interposed between the
vehicle body-side tube and the axle-side tube is seated on a spring receiver supported
so as to not to be rotatable with respect to the axle bracket in the axle-side tube.
The hydraulic shock absorber comprises a spring receiver that is supported so as to
not be rotatable with respect to the axle bracket. The spring receiver is divided
into a spring receiver base portion that has an outer diameter smaller than an inner
periphery of the axle-side tube, and a spring receiver cylindrical portion that is
inserted into an inner periphery of the axle-side tube and the suspension spring is
seated thereon. A lower end engagement portion provided at a lower end of the spring
receiver cylindrical portion is seated on an upper end engagement portion provided
at an upper end of the spring receiver base portion, so that the spring receiver cylindrical
portion is concentrically set to the axle-side tube.
[0008] The present invention will be more fully understood from the detailed description
given below and from the accompanying drawings which should not be taken to be a limitation
on the invention, but are for explanation and understanding only.
The drawings:
[0009]
FIG. 1 is a sectional view showing the entire hydraulic shock absorber;
FIG. 2 is a sectional view showing the lower portion of the hydraulic shock absorber
shown in FIG. 1;
FIG. 3 is a sectional view showing the upper and intermediate portions of the hydraulic
shock absorber shown in FIG. 1.;
FIG. 4 is a sectional view showing a spring load adjusting portion;
FIGS. 5A to 5C show a nut, wherein FIG. 5A is a sectional view, FIG.
5B is a front view, and FIG. 5C is a rear view;
FIGS. 6A and 6B show a slider, wherein FIG. 6A is a side view and FIG. 6B is a front
view;
FIGS. 7A and 7B shows a spring receiver base portion, wherein FIG. 7A is a side view
and FIG. 7B is a rear view;
FIGS. 8A to 8C show a spring receiver cylindrical portion, wherein FIG. 8A is a sectional
view, FIG. 8B is a side view, and FIG. 8C is a bottom view.
FIG. 9 is a sectional view showing that an axle bracket is inverted and assembled;
FIGS. 10A and 10B show fall prevention means of the spring receiver, wherein FIG.
10A is a rear view showing that the spring receiver is erected, and FIG. 10B is a
rear view showing that the spring receiver is inverted;
FIGS. 11A and 11B show fall prevention means of the spring receiver, wherein FIG.
11A is a rear view showing that the spring receiver is erected, and FIG. 11B is a
rear view showing that the spring receiver is inverted;
FIGS. 12A and 12B show fall prevention means of the spring receiver, wherein FIG.
12A is a rear view showing that the spring receiver is erected, and FIG. 12B is a
rear view showing that the spring receiver is inverted; and
FIGS. 13A and 13B show fall prevention means of the spring receiver, wherein FIG.
13A is a rear view showing that the spring receiver is erected, and FIG. 13B is a
rear view showing that the spring receiver is inverted.
[0010] A front fork (a hydraulic shock absorber) 10 is an inverted front fork in which an
outer tube 11 is disposed on the side of the vehicle body, and an inner tube 12 is
disposed on the side of a wheel. As shown in FIGS. 1 to 3, the inner tube 12 is slidably
inserted into the outer tube 11 through a guide bush 11A fixed to an inner periphery
of an opening of a lower end of the outer tube 11 and a guide bush 12A fixed to an
outer periphery of an opening of an upper end of the inner tube 12. A reference symbol
11B represents an oil seal, and a reference symbol 11C represents a dust seal. A cap
13 is threadedly engaged in a liquid-tight manner with the opening of the upper end
of the outer tube 11, and the outer tube 11 is provided at its outer periphery with
vehicle body-side mounting members. An axle bracket 15 is threadedly engaged in a
liquid-tight manner with the opening of the lower end of the inner tube 12 to form
a bottom of the inner tube 12, and the axle bracket 15 is formed with an axle mounting
hole 15A.
[0011] The front fork 10 defines an annular oil chamber 17 defined by the inner periphery
of the outer tube 11, the outer periphery of the inner tube 12 and the two guide bushes
11A and 12A.
[0012] The front fork 10 is provided with a closed end cup shaped liquid-tight partition
wall member 19 through an O-ring around an inner periphery of an upper end side of
the inner tube 12. A working oil chamber 21 is defined in the partition wall member
19 at a position lower than the rod guide portion 19A, and an oil reservoir chamber
22 is defined in the partition wall member at a position higher than the rod guide
portion. In the oil reservoir chamber 22, its lower region is an oil chamber 22A,
and an upper region is an air chamber 22B. A guide bush 12A provided on an outer periphery
of an upper end of the partition wall member 19, which projects from the inner tube
12, and slides on an inner periphery of an outer tube 11.
[0013] In the front fork 10, a piston rod 23 mounted on the outer tube 11 is slidably inserted
into the rod guide portion 19A of the partition wall member 19. More specifically,
a hollow piston rod 23 is threadedly engaged with a mounting collar 24 threadedly
engaged with a lower end of a center portion of a cap 13, and this is fixed by a lock
nut 24A.
[0014] A piston 26 which comes into slidable contact with an inner periphery of an inner
tube 12 is fixed to a piston bolt 25 threadedly engaged with a tip end of the piston
rod 23 inserted into the inner tube 12 from a rod guide portion 19A of the partition
wall member 19. Oil chamber 21 is defined in a piston rod-side oil chamber 21A in
which the piston rod 23 is accommodated and in a piston side oil chamber 21B in which
the piston rod 23 is not accommodated. The piston 26 is fixed by a nut 27.
[0015] The front fork 10 brings the annular oil chamber 17 into continuous communication
with the piston rod-side oil chamber 21A through an oil hole 28 formed in the inner
tube 12.
[0016] An upper spring receiver 31 of the front fork 10 is mounted on a side of the lower
end surface facing the piston side oil chamber 21B of the piston 26. A lower spring
receiver 32 is disposed on a bottom of the inner tube 12 formed by the axle bracket
15, and a main suspension spring 33 is interposed between the upper spring receiver
31 and the lower spring receiver 32. The entire main suspension spring 33 is immersed
in a piston side oil chamber 21B. The front fork 10 absorbs an impact force received
from a road surface when the vehicle runs by expansion, compression and vibration
of the main suspension spring 33. At that time, the spring load adjusting apparatus
100 vertically moves the lower spring receiver 32, and the spring load of the main
suspension spring 33 can be adjusted.
[0017] In the front fork 10, the piston 26 has a damping force generating apparatus 40 (FIG.
3).
[0018] The damping force generating apparatus 40 includes a compression side flow path 41
and an expansion side flow path 42. The compression side flow path 41 is opened and
closed by a compression side disk valve 41A (a compression side damping valve) which
is backed up by a valve stopper 41B. The expansion side flow path 42 is opened and
closed by an expansion side disk valve 42A (an expansion side damping valve) which
is backed up by a valve stopper 42B. The valve stopper 41B, the valve 41A, the piston
26, the valve 42A, and the valve stopper 42B constitute a valve assembly inserted
into the piston bolt 25, and the valve assembly is sandwiched and fixed by the nut
27 which is threadedly engaged with the piston bolt 25.
[0019] The damping force generating apparatus 40 is provided at a center of the cap 13 with
a later-described damping force adjusting apparatus 40A. A needle valve 75 of the
damping force adjusting apparatus 40A is inserted into a hollow portion of the piston
rod 23, and an opening degree of the bypass passage 45 provided in the piston rod
23 is adjusted by vertical motion of a needle valve 75. The bypass passage 45 bypasses
the piston 26, and brings the piston rod-side oil chamber 21A and the piston side
oil chamber 21B into communication with each other.
[0020] In a compression side stroke, the damping force generating apparatus 40 generates
a compression side damping force by a passage resistance of the bypass passage 45
whose opening amount is adjusted by the needle valve 75 in the low speed region, and
generates a compression side damping force by bending deformation of the compression
side disk valve 41A in the intermediate/high speed region. In an expansion side stroke,
the damping force generating apparatus 40 generates the expansion side damping force
by the passage resistance of the bypass passage 45 whose opening amount is adjusted
by the needle valve 75 in the low speed region, and generates the expansion side damping
force by bending deformation of the expansion side disk valve 42A in the intermediate/high
speed region. The expansion, compression and vibration of the main suspension spring
33 are controlled by the compression side damping force and the expansion side damping
force.
[0021] In the front fork 10, a stopper rubber 13A and a stopper plate 13B on which an upper
end of the partition wall member 19 provided on the inner tube 12 strikes in the most
compressed stroke are fixed to a lower end surface of the cap 13, and the most compressed
stroke is limited by the stopper rubber 13A.
[0022] The front fork 10 has a rebound spring 48 interposed between a spring sheet 46 which
is fixed using a stopper ring 46A to a lower end surface of the partition wall member
19 on the side of an upper end of the inner tube 12 facing the piston rod-side oil
chamber 21A, and a spring sheet 47 retained to a stopper ring 47A provided on the
piston rod 23. When the front fork 10 is at the maximum expansion position, the spring
sheet 46 of the side of the partition wall member 19 pressurizes the rebound spring
48 between the spring sheet 47 and the partition wall member 19, thereby limiting
the maximum position in the expanded stroke.
[0023] Therefore, in the front fork 10, a cross-sectional area S1 of the annular oil chamber
17 comprising an annular gap between the outer tube 11 and the inner tube 12 is greater
than a cross-sectional area (area surrounded by an outer diameter) S2 of the piston
rod 23 (S1>S2).
[0024] The rod guide portion 19A of the partition wall member 19 and the spring sheet 46
are provided with a check valve 50 which permits oil to flow from the oil reservoir
chamber 22 into the piston rod-side oil chamber 21A in the compression side stroke,
and which prevents oil from flowing from the piston rod-side oil chamber 21A into
the oil reservoir chamber 22 in the expansion side stroke.
[0025] The rod guide portion 19A of the partition wall member 19 has no oil seal fixed on
a periphery of the piston rod 23. Thus, a fine flow path (orifice) 51 (not shown)
which brings the piston rod-side oil chamber 21A and the oil reservoir chamber 22
into communication with each other is formed by a fine gap formed around the piston
rod 23 by the bush which is press-fitted to the inner periphery of the check valve
50. The fine flow path 51 is pieced in the rod guide portion 19A of the partition
wall member 19, and may be formed as an orifice that puts the piston rod-side oil
chamber 21A and the oil reservoir chamber 22 in communication with each other.
[0026] The hydraulic shock absorber 10 is operated in the following manner.
(Compression side stroke)
[0027] An entering capacity amount of working oil of the piston rod 23 which enters the
inner tube 12 during the compression side stroke is sent to the annular oil chamber
17 from the oil chamber 21A of the inner periphery of the inner tube 12 through the
oil hole 28 of the inner tube 12. At that time, since the increased capacity amount
ΔS1 (supply amount) of the annular oil chamber 17 is greater than the increased capacity
amount ΔS2 of the piston rod 23, a shortage amount (ΔS1-ΔS2) of a necessary supply
amount of oil into the annular oil chamber 17 is supplied from the oil reservoir chamber
22 through the check valve 50.
[0028] In the compression side stroke, as described above, the compression side damping
force is generated by the passage resistance of the bypass passage 45 whose opening
amount is adjusted by the needle valve 75 in the low speed region, and the compression
side damping force is generated by the bending deformation of the compression side
disk valve 41A in the intermediate/high speed region.
(Expansion side stroke)
[0029] In the expansion side stroke, a retreating capacity amount of working oil of the
piston rod 23 which is retreated from the inner tube 12 is sent to the oil chamber
21A of the inner periphery of the inner tube 12 through the oil hole 28 of the inner
tube 12 from the annular oil chamber 17. At that time, since the reduced capacity
amount ΔS1 (discharge amount) of the annular oil chamber 17 is greater than the reduced
capacity amount ΔS2 of the piston rod 23, a surplus amount (ΔS1-ΔS2) of oil from the
annular oil chamber 17 is discharged into the oil reservoir chamber 22 through the
fine flow path 51.
[0030] In the expansion side stroke, as described above, the expansion side damping force
is generated by the passage resistance of the bypass passage 45 whose opening degree
is adjusted by the needle valve 75 in the low speed region, and the expansion side
damping force is generated by the bending deformation of the expansion side disk valve
42A in the intermediate/high speed region. The expansion side damping force is also
generated by the passage resistance of the fine flow path 51.
[0031] The damping force adjusting apparatus 40A will be explained below.
[0032] As shown in FIG.3, the damping force adjusting apparatus 40A includes a first adjusting
portion 70 and a second adjusting portion 80 at the cap 13 that is provided at an
upper portion of the front fork 10. In the first adjusting portion, two push rods
61 and 62, which are concentrically inserted, are inserted into the hollow portion
of the piston rod 23 (the push rod 62 is inserted into the hollow portion of the piston
rod 23, and the push rod 61 is inserted into the hollow portion of the push rod 62),
and the push rod 61 is moved in the axial direction. The second adjusting portion
moves the push rod 62 in the axial direction.
[0033] The first adjusting portion 70 adjusts a damping force, which is caused by the passage
resistance of the bypass passage 45, by moving the needle valve 75. The second adjusting
portion 80 adjusts a damping force, which is caused by the bending deformation of
the compression side disk valve 41A, by adjusting the set load of a spring 87 that
biases the compression side disk valve 41A in a closing direction. Structures of the
first adjusting portion 70 and the second adjusting portion 80, a damping force adjusting
structure using the needle valve 75, and a damping force adjusting structure using
the spring 87 will be described.
[0034] (Structures of first adjusting portion 70 and second adjusting portion 80) (FIG.
3)
[0035] A cap assembly 90A is formed by threadedly engaging the mounting collar 24 with the
lower end opening of the cap 13. The cap 13 of the cap assembly 90A is threadedly
engaged in a liquid tight manner with an upper end opening of the outer tube 11 through
the O-ring 91. An upper end of the piston rod 23 is threadedly engaged with a lower
end of the mounting collar 24 and is fixed by the lock nut 24A. A stopper rubber 13A
is fitted to an annular recess that is formed by the mounting collar 24 and the cap
13 of the cap assembly 90A, and a stopper plate 13B is fitted to an outer periphery
of the mounting collar 24. A stopper ring 13C locking the stopper plate 13B is fitted
to the outer periphery of the mounting collar.
[0036] An adjusting assembly 90B is mounted on the mounting collar 24 and the cap 13 of
the cap assembly 90A. The adjusting assembly 90B includes a first adjusting bolt 71
that forms the first adjusting portion 70, a second adjusting bolt 81 that forms the
second adjusting portion 80, and first and second adjusting nuts 72 and 82 that correspond
to the adjusting bolts 71 and 81, respectively. The first adjusting nut 72 includes
a screw hole 72A with which a screw portion 71A of the corresponding first adjusting
bolt 71 is threadedly engaged, and a guide hole 72B into which a guide portion 81B
of the adjusting bolt 81 is inserted. The second adjusting nut 82 includes a screw
hole 82A with which a screw portion 81A of the corresponding second adjusting bolt
81 is threadedly engaged, and a guide hole 82B into which a guide collar 71B fitted
to the adjusting bolt 71 is inserted. Accordingly, if the first adjusting bolt 71
is rotated, the first adjusting nut 72 threadedly engaged with the adjusting bolt
71 is prevented from being rotated and is guided in the axial direction by the engagement
between the guide hole 72B of the adjusting nut 72 and the guide portion 81B of the
adjusting bolt 81. Therefore, the first adjusting nut is vertically moved in the axial
direction. Meanwhile, if the second adjusting bolt 81 is rotated, the second adjusting
nut 82 threadedly engaged with the adjusting bolt 81 is prevented from being rotated
and is guided in the axial direction by the engagement between the guide hole 82B
of the adjusting nut 82 and the guide collar 71B of the adjusting bolt 71. Therefore,
the second adjusting nut is vertically moved in the axial direction.
[0037] The first adjusting bolt 71 of the first adjusting portion 70 and the second adjusting
bolt 81 of the second adjusting portion 80, which constitute the adjusting assembly
90B, are inserted in a liquid tight manner into the two loading holes, which are juxtaposed
at positions separate from the center of the cap 13, from the rear side of the cap
13 with O-rings 73 and 83 in plan view of the cap 13 constituting the cap assembly
90A. Further, the first and second adjusting bolts 71 and 81 and the adjusting nuts
72 and 82 are received in the central recess 92 of the cap assembly 90A that is formed
by threadedly engaging the mounting collar 24 with the cap 13. Flange portions 71C
and 81C of the adjusting bolts 71 and 81 are abutted on the lower surface of the cap
13, and the lower end surfaces of the adjusting bolts 71 and 81 approach the bottom
of the central recess 92 that is formed by the mounting collar 24. The adjusting nuts
72 and 82 are received in the central recess 92, which is formed by the mounting collar
24, so as to slide on the inner periphery of the central recess. The push rod 61,
which projects from the hollow portions of the piston rod 23, and the push rod 62,
penetrates a center hole 82C of the second adjusting nut 82 and is abutted against
the lower end surface of the first adjusting nut 72. The push rod 62, which projects
from the hollow portion of the piston rod 23, is abutted against the lower end surface
of the second adjusting nut 82 around the center hole 82C.
[0038] Accordingly, an upper end operating portion 70A of the first adjusting bolt 71 of
the first adjusting portion 70 and an upper end operating portion 80A of the second
adjusting bolt 81 of the second adjusting portion 80 are juxtaposed so as to be flush
with the upper surface of the cap 13 at positions that are separated from the center
of the cap 13 in plan view of the cap 13 constituting the cap assembly 90A. Further,
the first adjusting bolt 71 of the first adjusting portion 70 is pivotally supported
not to move in the axial direction only by the rotation of the cap 13, and the second
adjusting bolt 81 of the second adjusting portion 80 is also pivotally supported not
to move in the axial direction only by the rotation of the cap 13. Accordingly, if
the first adjusting bolt 71 of the first adjusting portion 70 is rotated, it is possible
to vertically move the first adjusting nut 72, which is threadedly engaged with the
first adjusting bolt 71, in the axial direction, and to move the push rod 61, which
is abutted against the first adjusting nut 72, in the axial direction. Meanwhile,
if the second adjusting bolt 81 of the second adjusting portion 80 is rotated, it
is possible to vertically move the second adjusting nut 82, which is threadedly engaged
with the second adjusting bolt 81, in the axial direction, and to move the push rod
62, which is abutted against the second adjusting nut 82, in the axial direction.
[0039] (Damping force adjusting structure using needle valve 75) (FIG. 3)
[0040] An inner base 74 is inserted into a lower end of the hollow portion of the piston
rod 23, and the lower end surface of the piston rod 23 and an inner diameter step
portion of the piston bolt 25 sandwich and fix the inner base 74. The inner base 74
may be press-fitted into the hollow portion of the piston rod 23. The needle valve
75 is inserted in a liquid tight manner into the inner periphery of the inner base
74 fixed to the piston rod 23 in this manner. A spring 76, which is interposed between
an intermediate flange portion 75A of the needle valve 75 and an upper end surface
of the inner base 74, biases the needle valve 75 in the axial direction toward the
upper side (in a valve opening direction), and makes the upper end surface of the
needle valve 75 be abutted against the lower end surface of the push rod 61.
[0041] If the first adjusting bolt 71 of the first adjusting portion 70 vertically moves
the push rod 61 in the axial direction as described above, the needle valve 75 that
is engaged with the push rod 61 in the axial direction can vertically move with respect
to the piston bolt 25, can move forward and rearward with respect to a valve sheet
of a vertical hole upper end of the bypass passage 45 provided in the piston bolt
25, and can adjust the opening degree of the bypass passage 45 and the compression
side damping force and the expansion side damping force that are caused by the passage
resistance of the bypass passage 45.
(Damping force adjusting structure using spring 87) (FIG. 3)
[0042] Long guide holes 23A extending in the axial direction are provided on both sides
of the lower end of the piston rod 23 in the radial direction, and both side projections
of the pushing piece 84 are slidably inserted into the guide holes 23A almost without
play. A lower end surface of the push rod 62 which is inserted into the hollow portion
of the piston rod 23 contacts directly an upper surface of the pushing piece 84. A
cross sectional portion of the needle valve 75 which is loosely inserted into the
lower end of the push rod 62 is loosely inserted into a circular hole formed in a
center of the pushing piece 84 such that the cross sectional portion can move in the
axial direction.
[0043] Spring receivers 85 which pushingly contacts both end projections of the pushing
piece 84 from below and a valve holding member 86 which pushingly contacts an upper
surface (back surface) of the compression side disk valve 41A are disposed around
a lower end (piston bolt 25) of the piston rod 23, and a valve holding member spring
87 is interposed between the spring receiver 85 and the valve holding member 86. The
spring receiver 85 is of a cup-like shape. The spring receiver 85 pushingly contacts
both side projections of the pushing piece 84 at an inner peripheral lower end of
the cup, and the spring receiver 85 allows the spring 87 to sit on an upper end outer
peripheral flange of the cup. The valve holding member 86 includes an annular holding
member 86A which continuously (or intermittently) pushingly contacts the entire circumference
of the compression side disk valve 41A at a position of appropriate outer diameter
of the upper surface, a slide portion 86B which is slid and guided by an upper end
outer periphery of the piston bolt 25, and an oil passage 86C which brings the piston
rod-side oil chamber 21A into communication with the compression side flow path 41,
the expansion side flow path 42 and the bypass passage 45. The valve holding member
86 allows the spring 87 to sit on the outer peripheral step portion.
[0044] If the adjusting bolt 81 of the second adjusting portion 80 moves the push rod 62
in the axial direction as described above, the pushing piece 84 against which the
lower end surface of the push rod 62 is in contact vertically moves the spring receiver
85 to expand and shrink the valve holding member spring 87, and a set load of the
spring 87 is adjusted. With this, the set load of the spring 87 biases the compression
side disk valve 41A in its closing direction through the valve holding member 86 so
that the compression side damping force via bending deformation of the compression
side disk valve 41A can be adjusted. The valve holding member 86 can be replaced by
one having different diameter of the holding member 86A. A valve holding member 86
having a holding member 86A of large diameter holds an outer peripheral side of the
compression side disk valve 41A, and the damping force is increased from a low speed
region of piston speed. A valve holding member 86 having a holding member 86A of small
diameter holds an inner peripheral side of the compression side disk valve 41A, and
increases the damping force in intermediate and high speed regions of piston speed.
[0045] A spring load adjusting apparatus 100, which moves vertically a spring receiver 32
and adjusts a spring load of the suspension spring 33, will be described below.
[0046] As shown in FIGS. 2 and 4, the spring load adjusting apparatus 100 is built in a
small diameter closed hole 16B of an axle bracket 15 that communicates with a large
diameter opening hole 16A threadedly engaged with the lower end of the inner tube
12. In the spring load adjusting apparatus 100, an adjusting bolt 101, which faces
the outside at a position deviated from an axle mounting hole 15A of the axle bracket
15, is inserted into the small diameter closed hole 16B from the outside of the axle
bracket 15. A slider 102, which is provided on a lower surface of a bottom 16C of
the small diameter closed hole 16B (slide surface) (the surface facing the lower end
of the spring receiver 32), can move straight in a direction intersecting the center
axis of the inner tube 12 (in the axial direction of the adjusting bolt 101) via a
rotation force of the adjusting bolt 101. A lower slant A1 of the spring receiver
32 (a spring receiver base portion 111 to be described below) is placed on an upper
slant A2 of the slider 102, and the spring receiver 32 is supported by the axle bracket
15 through the adjusting bolt 101, the slider 102, and a holder 103. The spring receiver
32 (a spring receiver base portion 111 and a spring receiver cylindrical portion 112
to be described below) is moved vertically by the rotation of the adjusting bolt 101,
so that the spring load of the suspension spring 33 is adjusted.
(1) The holder 103 of the adjusting bolt 101 is threadedly engaged in a liquid tight
manner with and fixed to a mounting hole 15B that intersects perpendicularly (or diagonally
intersects) to a center axis (the same as the center axis passing through the axle
mounting hole 15A of the inner tube 12 in a state in which the axle bracket 15 is
mounted on the inner tube 12) passing through the axle mounting hole 15A of the axle
bracket 15, and penetrates the small diameter closed hole 16B from the outside of
the axle bracket 15. As for the adjusting bolt 101, a rotation operating shaft 101A,
which includes a hexagonal socket on the outward end surface, is inserted in a liquid
tight manner into the holder 103, and a screw shaft 101B is inserted into the small
diameter closed hole 16B. As for the adjusting bolt 101, an intermediate step surface
of the rotation operating shaft 101A is pushingly contacted with an intermediate step
surface of the holder 103 in the axial direction, and an end surface of the screw
shaft 101B is pushingly contacted with a vertical wall of the small diameter closed
hole 16B. Accordingly, the free movement of the adjusting bolt in the axial direction
is limited. In addition, in the adjusting bolt 101, a ball 101D, which is elastically
pushed by a spring 101C mounted in a hole pierced on the outer periphery of the rotation
operating shaft 101A, can be sequentially engaged with engagement grooves 103A that
are formed at a plurality of positions on the inner periphery of the holder 103 in
a circumferential direction. Accordingly, the adjusting bolt is locked at an arbitrary
rotation operating position corresponding to each of the engagement grooves 103A with
a click feeling upon engagement.
(2) When the rotation operating shaft 101A of the adjusting bolt 101 is pivotally
attached to the axle bracket 15 as described in (1), a washer 104, a slider 102, and
a nut 105 are inserted into the screw shaft 101B of the adjusting bolt 101. That is,
washer 104 is abutted against the step surface that is formed at a boundary between
the rotation operating shaft 101A and the screw shaft 101B of the adjusting bolt 101.
The washer 104 forms a tetragon, and its lower side is abutted against the bottom
16C of the small diameter closed hole 16B of the axle bracket 15 to prevent the rotation.
The slider 102 is inserted into the screw shaft 101B of the adjusting bolt 101, and
the nut 105 in abutment with the slider 102 is threadedly engaged with a screw portion
of the screw shaft 101B. As shown in FIGS. 5A to 5C, the nut 105 includes a nut portion
105A and a quadrate plate 105B that is continuous with the nut portion 105A. A lower
side of the plate 105B is abutted against the bottom 16C of the small diameter closed
hole 16B of the axle bracket 15 to prevent rotation. As shown in FIGS. 6A and 6B,
the slider 102 forms a tetragon and includes a hole into which the screw shaft 101B
of the adjusting bolt 101 is inserted. A lower side of the slider is abutted against
the bottom 16C of the small diameter closed hole 16B of the axle bracket 15 to prevent
rotation, and its upper side is an upper slant A2.
(3) The spring receiver 32 is divided into a spring receiver base portion 111 and
a spring receiver cylindrical portion 112. When the spring receiver base portion 111
is inserted into the large diameter opening hole 16A and the small diameter closed
hole 16B of the axle bracket 15 and is engaged with the washer 104 and the slider
102 of the spring load adjusting apparatus 100, the spring receiver base portion is
supported while being not rotated relatively with respect to the axle bracket 15,
and has an outer diameter smaller than the inner periphery of the inner tube 12. The
spring receiver cylindrical portion 112 has a closed-end tubular shape and is inserted
into the inner periphery of the inner tube 12 with a small gap, so that the suspension
spring 33 can be seated (through a flange of a spring collar 113 in this embodiment).
A cylindrical outer peripheral surface of a downward convex (or concave) lower end
engagement portion 112A, which is provided at the lower end (bottom) of a cylindrical
portion 131 of the spring receiver cylindrical portion 112, is mounted on a round
hole-shaped inner peripheral surface of an upward concave (or convex) upper end engagement
portion 111A that is provided at an upper end of an annular head portion 121 of the
spring receiver base portion 111, so as to be self-aligned. The lower end engagement
portion 112A of the spring receiver cylindrical portion 112 is seated on the upper
end engagement portion 111A of the spring receiver base portion 111, and the spring
receiver cylindrical portion 112 can be concentrically set to the inner tube 12. Meanwhile,
in this embodiment, the cup-like spring collar 113 is fitted in a liquid tight manner
to the upper end opening portion of the spring receiver cylindrical portion 112 through
the O-ring 113A, and the flange of the spring collar 113 is placed on the upper end
surface of the spring receiver cylindrical portion 112. The spring receiver cylindrical
portion 112 and the spring collar 113 maintain an internal space which is integrally
fused to each other in a cavity, and the amount of oil to be charged into the oil
chamber 21 of the inner tube 12 is reduced and the weight is reduced.
[0047] As shown in FIGS. 7A and 7B, in the spring receiver base portion 111, a downward
projection 122 projects from a lower portion of the annular head portion 121. One
end surface of the downward projection 122 is the lower slant A1 and the other end
surface thereof is a lower vertical surface B in side view, and the lower slant A1
and the lower vertical surface B intersect with each other at an acute angle. The
spring receiver base portion 111 includes an upper end engagement portion 111A on
the inner periphery of the annular head portion 121. The spring receiver base portion
111 includes a U-shaped rotation preventing groove 123 which extends on the central
portion of the downward projection 122 in front view from the lower slant A1 to the
lower vertical surface B, which opens toward the lower side of the downward projection
122 and is loosely fitted to the outer diameter portion of the screw shaft 101B of
the adjusting bolt 101. The U-shaped groove 123 is loosely fitted to the outer diameter
portion of the screw shaft 101B of the adjusting bolt 101, so that the spring receiver
base portion 111 is prevented from being rotated with respect to the center axis of
the axle bracket 15. The spring receiver base portion 111 is engaged with a component
of the spring load adjusting apparatus 100, that is, is engaged with the outer diameter
portion of the adjusting bolt 101 in this embodiment, so that the spring receiver
base portion is supported while being not rotatable with respect to the axle bracket
15.
[0048] When being inserted into the small diameter closed hole 16B of the axle bracket 15,
the downward projection 122 of the spring receiver base portion 111 is interposed
between the slider 102 and the washer 104.Its lower slant A1 is placed on the upper
slant A2 of the slider 102, and the lower vertical surface B is abutted against the
end surface of the washer 104. The nut 105 and the slider 102 are moved straight by
the rotation of the adjusting bolt 101, and the spring receiver base portion 111 and
the spring receiver cylindrical portion 112 are moved vertically. At this time, circular
arc-shaped outer peripheral surfaces of projecting guide portions 124, which are provided
at two positions facing each other in a direction of the diameter of the lower end
outer periphery of the downward projection 122, are slidably guided by the circular
inner peripheral surface of the small diameter closed hole 16B. Therefore, the spring
receiver base portion 111 moves vertically without backlash. The cylindrical outer
peripheral surface of the cylindrical portion 131 is slidably guided by the inner
peripheral surface of the inner tube 12, so that the spring receiver cylindrical portion
112 moves vertically without backlash.
[0049] The spring receiver base portion 111 is inserted into the large diameter opening
hole 16A and the small diameter closed hole 16B of the axle bracket 15, the lower
slant A1 of the downward projection 122 is placed on the upper slant A2 of the slider
102, and the lower vertical surface B is abutted against the end face of the washer
104. At this time, the annular head portion 121 of the spring receiver base portion
111 has a small outer diameter which does not come in contact with the inner periphery
of the inner tube 12 inserted into the large diameter opening hole 16A in the large
diameter opening hole 16A. A projecting guide portion 124 of the spring receiver base
portion 111 has an outer diameter which comes in slide contact with the inner periphery
of the small diameter closed hole 16B in the small diameter closed hole 16B.
[0050] Meanwhile, when the axle bracket 15 is assembled to the front fork 10 that is threadedly
engaged with the lower end of the inner tube 12 in the spring load adjusting apparatus
100, upper and lower ends of the inner tube 12 and the axle bracket 15 are vertically
inverted to be in an inverted state as described below. In this case, the adjusting
bolt 101 is used as fall prevention means 140 of the spring receiver 32 (spring receiver
base portion 111), and projecting portions 123A, which form mooring portions 141 to
be moored on the outer diameter portion of the adjusting bolt 101, are provided on
both side walls of the lower end opening portion of the U-shaped groove 123.
(4) The axle bracket 15 is inserted into and threadedly engaged with the lower end
of the inner tube 12. The inner tube 12 and the axle bracket 15 may be assembled while
being in an erected state as shown in FIGS. 2 and 4, or may be assembled in an inverted
state where the upper and lower ends of the inner tube are vertically inverted as
described below. In this case, the adjusting bolt 101, the slider 102, the holder
103, the washer 104, and the nut 105 are assembled to the axle bracket 15 as described
above, and the spring receiver base portion 111 of the spring receiver 32 is inserted
into the axle bracket. The downward projection 122 of the spring receiver base portion
111 is engaged with the slider 102 and the washer 104. The U-shaped rotation preventing
groove 123 of the spring receiver base portion 111 is loosely fitted to the outer
diameter portion of the adjusting bolt 101, so that both projecting portions 123A
of the U-shaped groove 123 are moored on the outer diameter portion of the adjusting
bolt 101. However, the spring receiver cylindrical portion 112 of the spring receiver
32 is not inserted into the axle bracket 15 yet.
[0051] The lower end of the inner tube 12 is inserted into the inner periphery of the large
diameter opening hole 16A through the O-ring 106, which is fitted to an annular groove
of the inner periphery around the lower end of the large diameter opening hole 16A
of the axle bracket 15. One of the inner tube 12 and the axle bracket 15 is clamped
and the other thereof is rotated, so that the lower end of the inner tube 12 is threadedly
engaged with the screw portion provided above the O-ring 106 of the large diameter
opening hole 16A in the axle bracket 15. In this case, the washer 107 provided on
the large diameter opening hole 16A of the axle bracket 15 is seated at a step portion
of the boundary between the large diameter opening hole 16A and the small diameter
closed hole 16B. A tip of the lower end of the inner tube 12 threadedly engaged with
the large diameter opening hole 16A of the axle bracket 15 is pushingly contacted
with the washer 107, and the washer 107 is interposed the step portion between the
large diameter opening hole 16A and the small diameter closed hole 16B.
(5) The inner tube 12 threadedly engaged with the axle bracket 15 is in the erected
state, the spring receiver cylindrical portion 112 of the spring receiver 32 is inserted
into the inner tube 12 from the upper end opening of the inner tube 12, the lower
end engagement portion 112A of the spring receiver cylindrical portion 112 is seated
on the upper end engagement portion 111A of the spring receiver base portion 111,
and the spring receiver base portion 111 and the spring receiver cylindrical portion
112 are concentrically set without falling on the center axis of the inner tube 12.
The spring collar 113 of the above-mentioned (3) is fitted to the upper end opening
portion of the spring receiver cylindrical portion 112. Subsequently, the suspension
spring 33 inserted into the inner tube 12 is supported by the spring receiver 32 (the
spring receiver base portion 111 and the spring receiver cylindrical portion 112)
through the flange of the spring collar 113.
[0052] If the adjusting bolt 101 is threadedly moved in a state in which the front fork
10 is assembled, the projecting guide portion 124 of the spring receiver base portion
111 of the spring receiver 32 is guided by the inner peripheral surface of the small
diameter closed hole 16B of the axle bracket 15 through the lower slant A1 of the
downward projection 122 which are included in the spring receiver base portion 111
of the spring receiver 32, and the upper slant A2 of the slider 102, and moves vertically.
Further, the spring receiver cylindrical portion 112 is guided by the inner peripheral
surface of the inner tube 12 and moves vertically. The spring receiver 32 adjusts
the initial length of the suspension spring 33 between the spring receiver 31 on the
side of the piston rod 23 and the spring receiver 32, and adjusts the spring load
of the suspension spring 33.
[0053] As shown in FIGS. 8A to 8C, in the spring load adjusting apparatus 100, a vertical
groove 131A extending over the entire length of the cylindrical portion 131 is provided
on the outer periphery of the cylindrical portion 131 of the spring receiver cylindrical
portion 112 of the lower spring receiver 32 that slides on the inner periphery of
the inner tube 12. Accordingly, the oil chamber 21 in the upper portion of the lower
spring receiver 32 is brought into communication with a back surface chamber 21C of
the lower spring receiver 32, and as the lower spring receiver 32 moves vertically,
oil in the oil chamber 21 can be supplied to and discharged from the back surface
chamber 21C.
[0054] In the spring load adjusting apparatus 100, the slider 102 may directly be provided
with a screw portion (nut portion), or the nut may be fitted and fixed to the slider
102 so that the nut 105 separated from the slider 102 is not required, and the number
of parts can be reduced.
[0055] Since the spring receiver 32 is divided into the spring receiver base portion 111
and the spring receiver cylindrical portion 112 in the front fork 10, the following
effects can be obtained.
- (a) The spring receiver 32 is supported so as to be not rotatable with respect to
the axle bracket 15, and is divided into the spring receiver base portion 111 that
has an outer diameter smaller than the inner periphery of the inner tube 12, and the
spring receiver cylindrical portion 112 that is inserted into the inner periphery
of the inner tube 12,such that the suspension spring 33 can be seated thereon. Accordingly,
when the axle bracket 15 is threadedly rotated in order to be threadedly engaged with
the inner tube 12, the spring receiver is not rotated with respect to the axle bracket
15. That is, the spring receiver base portion 111, which is rotated as a single body,
has an outer diameter sufficiently smaller than the inner periphery of the inner tube
12. Accordingly, the spring receiver base portion is not engaged with the inner periphery
of the inner tube 12, thereby not preventing the thread rotation. Therefore, the axle
bracket 15 and the inner tube 12 are smoothly threadedly engaged with each other and
damage of the spring receiver 32 and the like is not caused.
- (b) The spring receiver cylindrical portion 112 is inserted into the inner periphery
of the inner tube 12 with a small gap, the lower end engagement portion 112A provided
at the lower end of the spring receiver cylindrical portion 112 is seated on the upper
end engagement portion 111A that is provided at the upper end of the spring receiver
base portion 111, and the spring receiver cylindrical portion 112 is concentrically
set to the inner tube 12. Further, the spring receiver base portion 111 can be assembled
without falling.
- (c) When the axle bracket 15 is provided with the spring load adjusting apparatus
100, and the spring receiver base portion 111 of the spring receiver 32 is supported
to be not rotatable with respect to the axle bracket 15 by being engaged with the
spring load adjusting apparatus 100, it is possible to achieve the above-mentioned
(a) and (b).
- (d) The lower vertical surface B of the spring receiver base portion 111 of the spring
receiver 32 is abutted against and engaged with the end surface of the washer 104
of the spring load adjusting apparatus 100, so that the spring receiver base portion
111 is supported to be not rotatable with respect to the axle bracket 15 by being
engaged with the washer 104 of the spring load adjusting apparatus 100.
- (e) The U-shaped rotation preventing groove 123, which is provided at the lower end
of the spring receiver base portion 111 of the spring receiver 32, is loosely fitted
to the outer diameter portion of the adjusting bolt 101. Accordingly, the spring receiver
base portion 111 is supported to be not rotatable with respect to the axle bracket
15 by being engaged with the adjusting bolt 101 of the spring load adjusting apparatus
100.
[0056] The front fork 10 includes the following structures in order to prevent the fall
of the spring receiver base portion 111 of the spring receiver 32 that has been previously
assembled to the axle bracket 15, when the axle bracket 15 is assembled by being rotated
relatively with respect to the lower end of the inner tube 12 from the upper side
to a direction indicated by an arrow N in an inverted state where the upper and lower
ends of the inner tube 12 and the axle bracket 15 are vertically inverted as shown
in FIG. 9.
[0057] That is, as shown in FIGS. 10A and 10B, in the front fork 10, before the axle bracket
15 is vertically inverted (when the axle bracket 15 is erected), the mooring portions
141 are provided to the spring receiver base portion 111 of the spring receiver 32,
which has been previously engaged with the adjusting bolt 101, the slider 102, and
the washer 104 on the side of the axle bracket 15. Further, when the axle bracket
15 is vertically inverted (when the axle bracket 15 is inverted), the fall prevention
means 140, which is moored at the mooring portions 141 of the spring receiver base
portion 111 in order to prevent the fall of the spring receiver base portion 111,
is provided on the side of the axle bracket 15.
[0058] In this embodiment, as shown in FIGS. 10A and 10B, the adjusting bolt 101 constituting
the spring load adjusting apparatus 100 is used as the fall prevention means 140.
The U-shaped groove 123 provided at the downward projection 122 of the spring receiver
base portion 111 of the spring receiver 32 is loosely fitted to the outer diameter
portion of the adjusting bolt 101. The projecting portions 123A, which are formed
on both side walls of the lower end opening portion of the U-shaped groove 123, are
used as the mooring portions 141 moored on the outer diameter portion of the adjusting
bolt 101. FIG. 10A shows the adjusting bolt 101 and the spring receiver base portion
111 when the axle bracket 15 is erected, and FIG. 10B shows the adjusting bolt 101
and the spring receiver base portion 111 when the axle bracket 15 is inverted.
[0059] Accordingly, the front fork 10 is provided with the fall prevention means 140 and
the mooring portion 141, so that the following effects can be obtained.
- (a) When the upper and lower ends of the inner tube 12 are vertically inverted and
the axle bracket 15 is assembled to the lower end of the inner tube 12 from above,
the mooring portions 141 of the spring receiver 32, which has been previously assembled
to the axle bracket 15, are moored at the fall prevention means 140 that is provided
on the side of the axle bracket 15, thereby preventing the fall.
- (b) When the spring receiver 32 is assembled to the axle bracket 15 to be not rotatable
with respect to the axle bracket 15, the spring receiver 32 does not fall due to the
above-mentioned (a) even though the axle bracket 15 is vertically inverted. Accordingly,
it is possible to stably maintain an assembling state in which the spring receiver
is not rotatable with respect to the axle bracket 15, and troublesome reassembling
in the axle bracket 15 is not caused.
- (c) Both projecting portions 123A (mooring portions 141) of the lower end opening
portion of the U-shaped groove 123 provided at the end of the spring receiver 32,
which has been previously assembled to the axle bracket 15, are moored on the outer
diameter portion of the adjusting bolt 101 (fall prevention means 140) of the spring
load adjusting apparatus 100 that is included in the axle bracket 15, thereby preventing
the fall.
- (d) The U-shaped groove 123 of the lower end of the spring receiver 32 is loosely
fitted to the outer diameter portion of the adjusting bolt 101 of the spring load
adjusting apparatus 100, and it is possible to stably maintain an assembling state
in which the spring receiver 32 is not rotatable with respect to the axle bracket
15.
[0060] FIGS. 11A and 11B show the modifications of the fall prevention means 140 and the
mooring portion 141 of the front fork 10. That is, the adjusting bolt 101 constituting
the spring load adjusting apparatus 100 is used as the fall prevention means 140.
A rotation preventing long hole 151 (having a function of preventing the rotation
of the spring receiver base portion 111 similar to the U-shaped groove 123 instead
of the U-shaped rotation preventing groove 123), which is provided at the downward
projection 122 of the spring receiver base portion 111 of the spring receiver 32,
is loosely fitted to the outer diameter portion of the adjusting bolt 101. A lower
end closed portion 151A of the long hole 151 is used as the mooring portion 141 that
is moored on the outer diameter portion of the adjusting bolt 101. According to this,
the following effects can be obtained.
- (a) The lower end closed portion 151A (mooring portions 141) of the long hole 151
provided at the lower end of the spring receiver 32, which has been previously assembled
to the axle bracket 15, is moored on the outer diameter portion of the adjusting bolt
101 (fall prevention means 140) of the spring load adjusting apparatus 100 that is
included in the axle bracket 15, thereby preventing the fall.
- (b) The long hole 151 of the lower end of the spring receiver 32 is loosely fitted
to the outer diameter portion of the adjusting bolt 101 of the spring load adjusting
apparatus 100, and it is possible to stably maintain an assembling state in which
the spring receiver 32 is not rotatable with respect to the axle bracket 15.
[0061] FIGS. 12A and 12B show the modifications of the fall prevention means 140 and the
mooring portion 141 of the front fork 10. An annular projecting portion, which is
provided around the spring receiver 32 (spring receiver base portion 111) in the axle
bracket 15, that is, the above-mentioned washer 107 in this embodiment, is used as
the fall prevention means 140. A projecting portion provided on the outer periphery
of the spring receiver base portion 111, that is, the projecting guide portion 124
in this embodiment, is used as the mooring portion 141 that is moored to the washer
107 on the side of the axle bracket 15. The washer 107 provided at the lower end of
the large diameter opening hole 16A of the axle bracket 15 is moored by the O-ring
106 that is fitted to the annular groove formed near the lower end of the large diameter
opening hole 16A, and is not separated. The projecting guide portion 124 of the spring
receiver base portion 111 is moored at the washer 107, thereby preventing the fall.
According to this, the following effects can be obtained.
- (a) The projecting guide portion 124 (mooring portion 141) provided on the outer periphery
of the spring receiver 32 (spring receiver base portion 111), which has been previously
assembled to the axle bracket 15, is moored at the washer 107 (fall prevention means
140) provided around the spring receiver 32 (spring receiver base portion 111) in
the axle bracket 15, thereby preventing the fall.
- (b) The U-shaped groove 123 of the lower end of the spring receiver 32 (spring receiver
base portion 111) is loosely fitted to the outer diameter portion of the adjusting
bolt 101 of the spring load adjusting apparatus 100, and it is possible to stably
maintain an assembling state in which the spring receiver 32 (spring receiver base
portion 111) is not rotatable with respect to the axle bracket 15.
[0062] FIGS. 13A and 13B show the modifications of the fall prevention means 140 and the
mooring portion 141 of the front fork 10. That is, an inner peripheral surface of
the small diameter closed hole 16B, which is provided around the spring receiver 32
(spring receiver base portion 111) in the axle bracket 15, is used as the fall prevention
means 140. A projecting portion, which is provided on the outer periphery of the spring
receiver base portion 111, that is, a projecting guide portion 124 in this embodiment
is used as the mooring portion 141 that is moored while being lightly press-fitted
to the inner peripheral surface of the small diameter closed hole 16B. According to
this, the following effects can be obtained.
- (a) The projecting guide portion 124 (mooring portion 141) provided on the outer periphery
of the spring receiver 32 (spring receiver base portion 111), which has been previously
assembled to the axle bracket 15, is lightly press-fitted to the inner peripheral
surface (fall prevention means 140) provided around the spring receiver 32 (spring
receiver base portion 111) in the axle bracket 15, thereby preventing the fall.
- (b) The U-shaped groove 123 of the lower end of the spring receiver 32 (spring receiver
base portion 111) is loosely fitted to the outer diameter portion of the adjusting
bolt 101 of the spring load adjusting apparatus 100, and it is possible to stably
maintain an assembling state in which the spring receiver 32 (spring receiver base
portion 111) is not rotatable with respect to the axle bracket 15.
[0063] Meanwhile, in the front fork 10, the O-ring is fitted to the outer peripheral groove
of the lower spring receiver 32 (spring receiver cylindrical portion 112), so that
the lower spring receiver 32 may be fitted in a liquid tight manner to the inner periphery
of the inner tube 12 in the inner tube 12, and the oil chamber 21 of the upper portion
of the lower spring receiver 32 may be sealed in a liquid tight manner against the
back surface chamber 21C of the lower spring receiver 32. According to this, the vertical
movement of the lower spring receiver 32 in the inner tube 12 causes the oil level
of the oil reservoir chamber 22 to vertically move through the working oil chamber
21 of the inner tube 12. Therefore, the spring load of the suspension spring 33 is
adjusted by the vertical movement of the lower spring receiver 32, and the air chamber
22B is expanded or compressed by the upward movement of the oil level of the oil reservoir
chamber 22. As a result, it is also possible to adjust the spring load of the air
spring.
[0064] As heretofore explained, embodiments of the present invention have been described
in detail with reference to the drawings. However, the specific configurations of
the present invention are not limited to the illustrated embodiments but those having
a modification of the design within the range of the presently claimed invention are
also included in the present invention.
[0065] Although the invention has been illustrated and described with respect to several
exemplary embodiments thereof, it should be understood by those skilled in the art
that the foregoing and various other changes, omissions and additions may be made
to the present invention without departing from the spirit and scope thereof. Therefore,
the present invention should not be understood as limited to the specific embodiment
set out above, but should be understood to include all possible embodiments which
can be encompassed within a scope of equivalents thereof with respect to the features
set out in the appended claims.
1. A hydraulic shock absorber in which a lower end of an axle-side tube slidably inserted
into a vehicle body-side tube is threadedly engaged with an axle bracket, and
a lower end of a suspension spring interposed between the vehicle body-side tube and
the axle-side tube is seated on a spring receiver supported to be not rotatable with
respect to the axle bracket in the axle-side tube, the hydraulic shock absorber comprising:
a spring receiver that is supported to be not rotatable with respect to the axle bracket,
the spring receiver being divided into a spring receiver base portion that has an
outer diameter smaller than an inner periphery of the axle-side tube, and a spring
receiver cylindrical portion that is inserted into an inner periphery of the axle-side
tube and the suspension spring is seated thereon,
wherein a lower end engagement portion provided at a lower end of the spring receiver
cylindrical portion is seated on an upper end engagement portion provided at an upper
end of the spring receiver base portion, so that the spring receiver cylindrical portion
is concentrically set to the axle-side tube.
2. The hydraulic shock absorber according to claim 1,
wherein the axle bracket is provided with a spring load adjusting portion that adjusts
a spring load of the suspension spring by vertically moving the spring receiver, and
the spring receiver base portion of the spring receiver is supported to be not rotatable
with respect to the axle bracket by being engaged with the spring load adjusting portion.
3. The hydraulic shock absorber according to claim 2,
wherein the spring load adjusting portion supports an adjusting bolt by the axle bracket
so that the adjusting bolt is rotatable, a washer being abutted against a step surface
of one end side of the adjusting bolt, a slide inserted into the other end side of
the adjusting bolt, the slide capable of straight movement in a direction intersecting
a center axis of the axle-side tube, by a rotation force of the adjusting bolt, a
lower slant of the spring receiver base portion placed on an upper slant of the slider,
the lower vertical surface of the spring receiver base portion abutted against an
end surface of the washer, the spring receiver base portion and the spring receiver
cylindrical portion movable vertically by the rotation of the adjusting bolt.
4. The hydraulic shock absorber according to claim 3,
wherein a U-shaped rotation preventing groove, which is provided at the lower end
of the spring receiver base portion of the spring receiver, is loosely fitted to an
outer diameter portion of the adjusting bolt.
5. The hydraulic shock absorber according to any one of claims 1 to 4,
wherein the spring receiver cylindrical portion has a closed-end tubular cylindrical
shape, a cup-like spring collar is fitted in a liquid tight manner to an upper end
opening portion of the spring receiver cylindrical portion, and
a flange of the spring collar is placed on an upper end surface of the spring receiver
cylindrical portion.
6. The hydraulic shock absorber according to any one of claims 1 to 5,
wherein the lower end engagement portion forms a downward convex cylindrical outer
peripheral surface, the cylindrical outer peripheral surface is mounted on a round
hole-shaped inner peripheral surface of an upward concave upper end engagement portion
that is provided at an upper end of an annular head portion of the spring receiver
base portion, so as to be self-aligned, and the lower end engagement portion of the
spring receiver cylindrical portion is seated on the upper end engagement portion
of the spring receiver base portion.
7. The hydraulic shock absorber according to claim 3,
wherein in the spring receiver base portion, a downward projection projects from a
lower portion of the annular head portion, one end surface of the downward projection
is the lower slant and the other end surface thereof is a lower vertical surface in
side view, the lower slant and the lower vertical surface intersect with each other
at an acute angle, and the upper end engagement portion is provided on the inner periphery
of the annular head portion.
8. The hydraulic shock absorber according to claim 3,
wherein the spring load adjusting portion includes a vertical groove, which extends
over the entire length of the cylindrical portion, on the outer periphery of the cylindrical
portion of the spring receiver cylindrical portion of the spring receiver that slides
on the inner periphery of the axle-side tube.